Patrick McGary and Beth Stadler - Dr. Alison B. Flatau

31 Pages·2007·3.12 MB·English

by  David Lilja

Electroplating of Galfenol and the
Evolution of Alloy Stoichiometry in
Galfenol Nanowires with Growth Length
Patrick McGary and Bethanie J.H. Stadler
Department of Electrical and Computer Engineering
University of Minnesota
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
Roadmap
(cid:190) Motivation: Artificial Cilia Transducers
(cid:190) Background: Alumina Nanopore Template Fabrication
(cid:190) Electrodeposition of Galfenol
(cid:131) Hull Cell Deposition and Characterization
(cid:131) Potentiostatic Thin Film Deposition
(cid:131) Potentiostatic Nanowire Deposition
(cid:190) Conclusion
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
A Model Acoustic Sensor
Cilia from inner ear cell
Cilia from outer ear cell Cilia from our lab!
Yost and Nelson
Fundamentals of Hearing
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
Artificial Cilia Transducers (ACTs)
Acoustic
Waves
Anodic Alumina
Matrix
Patterned Giant
Magnetostrictive
Magnetoresistance
Nanowires of
Sensors
Varying Lengths
High-bandwidth application will use fibers with varied resonant
frequencies or a variable resonant chamber to produce high spatial
resolution (eg: for underwater cameras).
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
(cid:190) Motivation: Artificial Cilia Transducers
(cid:190) Alumina Nanopore Templates
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
Alumina Templates
Side View Schematic Commercially Available Grown in our lab
Pore diameter/spacing controllable via anodization conditions
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
AAO Cross-sections:
Commercial vs. Homemade
(a) 150-350 nm pore diameter Whatman® AnodiscTM AAO template at
40,000X magnification
(b) 40 nm AAO template fabricated with the two-step anodization showing
more uniform channels at 43,000X
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
Nanowire Fabrication Procedures
(a) (b) (c) (d)
Alumina
Bulk Al
Aluminum
1st Anodization Oxide Removal 2nd Anodization
Electropolishing
(e) Alumina (f) (g) Alumina (h)
Alumina
Aluminum Barrier Layer Sputter Electrical Electrodeposit
Removal Removal Contact Nanowires
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
(cid:190) Motivation: Artificial Cilia Transducers
(cid:190) Alumina Nanopore Template Fabrication
(cid:190) Electrodeposition of Galfenol
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler
Electrochemical Deposition of Nanowires
V
ref (cid:153) Fabrication Process
R
D
• Sputter contact on
V
V the back
in
working
side of porous
I R
++ -- D D template
• Insulate contact
• 3 Electrode
Working
++ -- potentiostatic
++ -- Electrode
Counter ++ ++ -- --
++ ++ GGaa33++ -- --
++ ++ -- -- (Sample) electrodeposition
Electrode
++ ++ -- --
++ ++ -- --
++ ++ -- --
(Pt) Electrolyte contains
++ ++ -- -- (cid:153)
++ ++ FFee22++ -- --
Brett and Brett,
++ --
++ -- metal sulfate and
Electrochemistry:Principles
E , Methods, and boric acid or other
Applications, Oxford UP,
additives
New York, 1993, p 146.
Reference Electrode (Ag+/AgCl)
• pH ~2-7
Electrical and Computer Engineering
Patrick McGary www.ece.umn.edu/users/stadler